/*
 * Visualization of gradient information.
 *
 */

#include <vtkImageCast.h>
#include <vtkImageConstantPad.h>
#include <vtkImageEuclideanToPolar.h>
#include <vtkImageExtractComponents.h>
#include <vtkImageGaussianSmooth.h>
#include <vtkImageGradient.h>
#include <vtkImageHSVToRGB.h>
#include <vtkImageMagnify.h>
#include <vtkImageViewer.h>
#include <vtkMetaImageReader.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>

#include <iomanip>
#include <iostream>
#include <string>

int main(int argc, char* argv[])
{
//    if (argc < 2)
//    {
//        std::cout << "Usage: " << argv[0] << " fileName" << std::endl;
//        std::cout << "where: fileName is FullHead.mhd." << std::endl;
//        std::cout << "Note: The file FullHead.raw.gz must also be present in the "
//                     "same folder."
//                  << std::endl;
//        return EXIT_FAILURE;
//    }

//    std::string fileName = argv[1];

    std::string fileName = "/Users/dai/Desktop/vtk-examples/src/Testing/Data/FullHead.mhd";

    vtkNew<vtkNamedColors> colors;

    // Read the CT data of the human head.
    vtkNew<vtkMetaImageReader> reader;
    reader->SetFileName(fileName.c_str());
    reader->Update();

    vtkNew<vtkImageCast> cast;
    cast->SetInputConnection(reader->GetOutputPort());
    cast->SetOutputScalarTypeToFloat();

//    // Magnify the image.
//    vtkNew<vtkImageMagnify> magnify;
//    magnify->SetInputConnection(cast->GetOutputPort());
//    magnify->SetMagnificationFactors(2, 2, 1);
//    magnify->InterpolateOn();
//
//    // Smooth the data.
//    // Remove high frequency artifacts due to linear interpolation.
//    vtkNew<vtkImageGaussianSmooth> smooth;
//    smooth->SetInputConnection(magnify->GetOutputPort());
//    smooth->SetDimensionality(2);
//    smooth->SetStandardDeviations(1.5, 1.5, 0.0);
//    smooth->SetRadiusFactors(2.01, 2.01, 0.0);
//
//    // Compute the 2D gradient.
//    vtkNew<vtkImageGradient> gradient;
//    gradient->SetInputConnection(smooth->GetOutputPort());
//    gradient->SetDimensionality(2);

    // Convert the data to polar coordinates.
    // The image magnitude is mapped into saturation value,
    //  whilst the gradient direction is mapped into hue value.
    vtkNew<vtkImageEuclideanToPolar> polar;
//    polar->SetInputConnection(gradient->GetOutputPort());

    polar->SetInputConnection(cast->GetOutputPort());

    polar->SetThetaMaximum(255.0);

//    // Add a third component to the data.
//    // This is needed since the gradient filter only generates two components,
//    //  and we need three components to represent color.
//    vtkNew<vtkImageConstantPad> pad;
//    pad->SetInputConnection(polar->GetOutputPort());
//    pad->SetOutputNumberOfScalarComponents(3);
//    pad->SetConstant(200.0);
//
//    // At this point we have Hue, Value, Saturation.
//    // Permute components so saturation will be constant.
//    // Re-arrange components into HSV order.
//    vtkNew<vtkImageExtractComponents> permute;
//    permute->SetInputConnection(pad->GetOutputPort());
//    permute->SetComponents(0, 2, 1);

    // Convert back into RGB values.
    vtkNew<vtkImageHSVToRGB> rgb;
//    rgb->SetInputConnection(permute->GetOutputPort());

    rgb->SetInputConnection(polar->GetOutputPort());

    rgb->SetMaximum(255.0);

    // Set up a viewer for the image.
    // Note that vtkImageViewer and vtkImageViewer2 are convenience wrappers
    // around
    // vtkActor2D, vtkImageMapper, vtkRenderer, and vtkRenderWindow.
    // So all that needs to be supplied is the interactor.
    vtkNew<vtkImageViewer> viewer;
    viewer->SetInputConnection(rgb->GetOutputPort());
    viewer->SetZSlice(22);
    viewer->SetColorWindow(255.0);
    viewer->SetColorLevel(127.0);
    viewer->GetRenderWindow()->SetSize(512, 512);
    viewer->GetRenderer()->SetBackground(colors->GetColor3d("Silver").GetData());
    viewer->GetRenderWindow()->SetWindowName("ImageGradient");

    // Create the RenderWindowInteractor.
    vtkNew<vtkRenderWindowInteractor> iren;
    viewer->SetupInteractor(iren);
    viewer->Render();

    iren->Initialize();
    iren->Start();

    return EXIT_SUCCESS;
}